TY - JOUR

T1 - Comparative genomic analysis of Holospora spp., intranuclear symbionts of paramecia

AU - Garushyants, Sofya K.

AU - Beliavskaia, Alexandra Y.

AU - Malko, Dmitry B.

AU - Logacheva, Maria D.

AU - Rautian, Maria S.

AU - Gelfand, Mikhail S.

PY - 2018/4/16

Y1 - 2018/4/16

N2 - While most endosymbiotic bacteria are transmitted only vertically, Holospora spp., an alphaproteobacterium from the Rickettsiales order, can desert its host and invade a new one. All bacteria from the genus Holospora are intranuclear symbionts of ciliates Paramecium spp. with strict species and nuclear specificity. Comparative metabolic reconstruction based on the newly sequenced genome of Holospora curviuscula, a macronuclear symbiont of Paramecium bursaria, and known genomes of other Holospora species shows that even though all Holospora spp. can persist outside the host, they cannot synthesize most of the essential small molecules, such as amino acids, and lack some central energy metabolic pathways, including glycolysis and the citric acid cycle. As the main energy source, Holospora spp. likely rely on nucleotides pirated from the host. Holospora-specific genes absent from other Rickettsiales are possibly involved in the lifestyle switch from the infectious to the reproductive form and in cell invasion.

AB - While most endosymbiotic bacteria are transmitted only vertically, Holospora spp., an alphaproteobacterium from the Rickettsiales order, can desert its host and invade a new one. All bacteria from the genus Holospora are intranuclear symbionts of ciliates Paramecium spp. with strict species and nuclear specificity. Comparative metabolic reconstruction based on the newly sequenced genome of Holospora curviuscula, a macronuclear symbiont of Paramecium bursaria, and known genomes of other Holospora species shows that even though all Holospora spp. can persist outside the host, they cannot synthesize most of the essential small molecules, such as amino acids, and lack some central energy metabolic pathways, including glycolysis and the citric acid cycle. As the main energy source, Holospora spp. likely rely on nucleotides pirated from the host. Holospora-specific genes absent from other Rickettsiales are possibly involved in the lifestyle switch from the infectious to the reproductive form and in cell invasion.

KW - Ciliates

KW - Endosymbionts

KW - Genome

KW - Holospora

KW - Nuclear symbionts

KW - Paramecia

KW - Rickettsiales

KW - endosymbionts

KW - ciliates

KW - IDENTIFICATION

KW - nuclear symbionts

KW - genome

KW - PERIPLASMIC PROTEIN

KW - EVOLUTION

KW - INFECTION PROCESS

KW - CAUDATUM

KW - DATABASE

KW - ELEGANS

KW - FREE-LIVING BACTERIA

KW - INSECTS

KW - OBTUSA

KW - paramecia

UR - http://www.scopus.com/inward/record.url?scp=85045765981&partnerID=8YFLogxK

U2 - 10.3389/fmicb.2018.00738

DO - 10.3389/fmicb.2018.00738

M3 - Article

C2 - 29713316

AN - SCOPUS:85045765981

VL - 9

SP - 738

JO - Frontiers in Microbiology

JF - Frontiers in Microbiology

SN - 1664-302X

IS - APR

M1 - 738

ER -